1. How many mg of lithium phosphide are in 18.0 mL of a 1.25 M solution?
Molarity = number of moles ÷ volume
According to the information in the question, molarity = 1.25 M, volume = 18.0 mL = 18/1000 = 0.018L
M = n/V
n = M × V
n = 1.25 × 0.018
n = 0.0225moles.
Using mole = mass/molar mass, to find the mass of lithium phosphide (Li3P)
Molar mass of Li3P = 6.9(3) + 31 = 51.7g/mol
mole = mass/molar mass
0.0225 = mass/51.7
mass = 1.16grams.
In milligrams (mg), mass of Li3P = 1.16 × 1000 = 1160mg
You must be logged in to post a comment.